Misaligned? (1 Viewer)

[vaubu]

When it comes to binoculars being out of alignment, how much is too much?

http://www.birdwatching.com/optics/education/alignment.html

When I test my bins in the way that is described in this link I find that mine are just barely out of alignment. I have a cheaper pair that are totally out of whack, but the ones that I use and love are midrange priced and from a reputable seller. I'm sure they would correct it for me, but I'm not sure the postage and the time without them would be worth it. I've often wondered if the image could be a bit sharper with them. Is it possible that proper alignment would sharpen the image a bit?

 

[ronh]

Eyestrain with prolonged use, and headaches, can result from a binocular whose images can barely be aligned. Fortunately your binocular's adjustment isn't that bad, and required this test to reveal a definite misalignment. But, this test is crude, as the instruction admits, and if it shows an error, correcting that error would likely be noticeable.

The main difference to me between binoculars that are tolerable and spot on are speed in getting the view. It takes that extra second for the eyes to misalign themselves to unnaturally accommodate the binocular. And an extra second also, to realign themselves naturally, after removing the binocular from the eyes.

The criticality of the situation depends on the direction of the misalignment. The eyes naturally "cross" when looking at close objects, so a misalignment that requires crossing is quite benign. But for the eyes to diverge outward or vertically is completely unnatural, and just a little of that gets to be a problem real fast.

That's textbook, but what do you do? It would hurt to be binocularless for a couple of weeks if you use it every day, but not so bad if only once a week. On the other hand, it's a worse transgression against nature to use a misaligned binocular, the more frequently you do so!

So here's my totally arbitrary personal test. Focus the binocular on a distant (half mile or more) object, then remove it from the eyes and relax a bit. Gaze at the object with naked eye. This will allow the eyes to align themselves to parallel. Now, look at the object through the binocular. If it takes more than 1.0 second (Mississippi-ONE, spoken quickly, as by Nawthunuz, not as by the likes of me, actually hailing from that state, who take about 1.3 seconds) to nail the view, ship it and pine away, you'll be glad you did.
Ron

 

[pshute]

If you wear glasses, be cautious of trusting that test, as it may be your glasses that are out of alignment. I tested my binoculars a few years ago after suspecting misalignment, and was disappointed to find they were out quite a bit.

Then I remembered I'd had headaches since one of the kids head-butted me in the face, and thought to have a look at my glasses from the side. They were obviously twisted so the lenses weren't parallel to each other. I twisted them back, and the headaches and apparent binocular misalignment were gone!

 

[vaubu]

Thanks pshute and ronh, I'd be happy to settle that I'm overthinking this. The cheap ones that I refered to as being "out of whack" give me a good idea of what misalignment really is; those things were doing some serious damage to my eyes and put to the test described above there is tangible proof as to why my eyes hurt so much after using them.

 

[ceasar]

You did not say what kind of binoculars you own. In many porro prism binoculars this problem can be fixed rather easily by a binocular technician. Some, however, might not be worth fixing.

Bob

 

[vaubu]

There not porro prisms but I'm sure they could be aligned and it's definitely a binocular worth maintaining, I'm just not sure if I'm overthinking the situation. I'm using my binoculars daily right now, but maybe if it is still bugging me in a month or so I may bite the bullet and send them off. For now I think I'm happy. I might take a stab at collimating the old pair; they are pretty unusable now and wouldn't be worth paying a repair fee on.

 

[ceasar]

You don't indicate how this misalignment came about. Did you bang them about? Did you notice the problem very shortly after you got them? How is the warranty on them? If you haven't owned them long you might be able to get them fixed. Your eyes are not going to get used to them.

Bob

 

[WJC]

You did not say what kind of binoculars you own. In many porro prism binoculars this problem can be fixed rather easily by a binocular technician. Some, however, might not be worth fixing.

Bob

I have tried to find QUALIFIED bino techs who I could recommend. There are many who will take your money. However, while many are good people, they may not know all they should. There is a BIG difference between 25 years experience and 1 year of experience 25 times!

Cheers,

WJC :bounce:

 

[vaubu]

My bins didn't get banged around, unless in the process of being shipped. They are definitely under warranty. I'm hesitant to send them off for two reasons. One being that I will be on holiday and will have some time to be out birding soon. The other reason is I'm just not sure if the misalignment is significant. When I look at a telephone wire, a thick telephone wire, the wires still meet on the horizontal plane, but the bottom of the wire looking through one barrel is touching the top of the image of the wire in the other barrel. Very slight misalignment. I have little experience owning bins and surmise that my having a problem with this is sort of anal retentive of me, but then again I don't know. The bins aren't alpha quality; they cost $300 with a lifetime warranty. Like many of us, I can spend anywhere from an hour to 8 hours looking at birds so it's nice to have confidence in the equipment that we use.

Those cheap bins that I also refer to were so whacked. Put under the same test (looking at a telephone wire through both barrels) one side had the wire near the bottom of the FOV, the other was near the top. I used these bins for a couple of months and began to have eye problems that lingered well beyond the time I would come home and tend to things around the house. It's likely I could have developed permanent damage if I had continued with them. But the condition of my better bins are much different. They are excellent, it's just now that I have this way of testing their alignment, which ronh pointed out is a crude test and correcting the discrepancy would not likely result in any significant change.

I guess ultimately I don't want to take advantage of the excellent customer service from Eagle Optics with something that is likely trivial, but truth be told, it's a pleasure to have something to post about in the forum, especially during the winter months.

 

[normjackson]

Have you tried using them on night sky? See if you can get a star to focus to a single point.
I liked dipped's suggestion at post #5 in this thread :
http://www.birdforum.net/showthread.php?t=212072
but when I tried it on several pairs, didn't get results expected.

 

[ceasar]

If you have had them less than 30 days you can send them back to Eagle and ask them to send you another one. It is their policy. Check it out on their website.

Bob

 

[ronh]

valbu,
You misread me I think. I said " But, this test is crude, as the instruction admits, and if it shows an error, correcting that error would likely be noticeable.". What I meant was, if so insensitive a test shows something, the something must be pretty big, especially considering that vertical alignment is the least well tolerated by the eyes.

But you don't seem to have any complaints with actual use of the binocular, is why my (admitettedly made up) time-to-view test to help establish if it's worth fixing. Did you test it for horizontal alignment too, using a straight vertical edge?

Yeah, I'd say keep it over Christmas and see some birds! (You know things must get flaky at Eagle Optics over the holidays, just like everywhere else.) With your newly heightnend awareness of the problem, if you STILL don't notice the slightest difficulty after a good round of birding, you'd just about have to think, why bother?

You could also go to a shop and look through some really expensive models, which are sure to be accurately adjusted, and see if you can nail the view any easier through them. Although, that is kind of a poisonous suggestion...
Ron

 

[vaubu]

@caesar - It's been more than 30 days, but EO has extended their grace period over the holidays, and I have been considering that option ...

@ronh - Indeed, I did misunderstand you. I tried your test, but got alot clumsy ascertaining the results. I can 'square' up on something in no time, there is alot of forgiveness in my focus knob. But sometimes when I've got a stable shot of say a duck or something, I feel like the plumage should be able to come into sharper focus. Bark on trees looks pretty sharp to me though. As for your poisonous suggestion, I don't live far from New York City and I know B&H carries some more expensive models. If I get the time I bet it would be interesting to check it out. Right now though I'm happy to get over the holiday hump of obligations and really spend some time with the Mergansers and Hawks that I've been taking quick peeks at all week. I got to watch a Red-tail tear apart a mole last night no more than 10 feet above my head. I wish I had brought my camera. Hopefully a similar opportunity will arise again soon. They've been very conspicuous lately. We watched another tear apart a squirrel at about the same distance from us in front of my daughter's school last week. Again though, no camera ...